Japan Aerospace Exploration Agency JAXA's Engineering Digital Innovation Center
Japan Aerospace Exploration Agency JAXA's Engineering Digital Innovation Center
Japan Aerospace Exploration Agency Civil Transport Team, Aviation Program Group
In order to apply the GMRES (Generalized Minimal RESidual) method, faster and more stable than the LU-SGS (Lower-Upper Symmetric Gauss-Seidel) method, to the three-dimensional hybrid-unstructured-grid finite-volume method Euler/Navier-Stokes solver JTAS (JAXA Tohoku-university Aerodynamic Simulation code), we developed a GMRES library code. Additionally, we solve some linear systems with simple coefficient matrices to examine stability of the GMRES method. As a result, we confirm the algorithm is more stable than Symmetric Gauss-Seidel method, and the preconditioning works well. We also find that under very ill-condition cases, the GMRES method shows unstable behavior.